VIBRATION experts have warned that the rising demand for on-site vibration testing of tools is leading to inconsistencies in standards.
They are concerned that some vibration tests are not following correct procedures to determine workers' exposure and that calculations could lull contractors into a false sense of security and even put workers at risk.
One concerned specialist said: 'It is good news that people are now testing on-site for real-life vibration data but some people are not following the British Standard that is specifically in place for the purpose.
'If they underestimate the vibration exposure they threaten to put tool users at risk and, if they overestimate it, they put the employer at risk by unnecessarily restricting worker productivity.'
BS 5349 sets out the process of measurement and calculation and gives minimum requirements to determine the typical exposure of workers, such as three samples for each tool and at least three different workers.
The expert said: 'I have seen recent tests where there are insufficient samples, where the calculations are not taken on three axes and where there is no standard deviation.
As a result, some of the measurements are just plain wrong.
'One manufacturer told me he had seen measured vibration values that were actually half what they were supposed to be.'
He called for contractors to ensure correct procedures were followed by consultants since the figures would be crucial in determining how long operatives could work on each tool and task.
nTool manufacturer Hilti is launching a user-friendly guide to the hand-arm vibration regulations on October 1.The guide includes advice on worker monitoring, tool selection, health risks and legal requirements.